Implement hit for chandles.
Implement hit for chandles.

Implement hit, drawHit and clearHit for the candles chart type.  This
fixes #164.

RobertoMalatesta/Flotr2,jessiejea/Flotr2,jessiejea/Flotr2,beastlike/Flotr2,HumbleSoftware/Flotr2,nicgallardo/Flotr2,nicgallardo/Flotr2,beastlike/Flotr2,alanponce/Flotr2,beastlike/Flotr2,jessiejea/Flotr2,alanponce/Flotr2,HumbleSoftware/Flotr2,RobertoMalatesta/Flotr2,alanponce/Flotr2